This invention relates to rotary engines and, more specifically, to the provision of a variable orifice prechamber in such engines.
Prior art of relevance includes U.S. Pat. No. 3,738,332 issued June 12, 1973 to Eyzat et al.
It has been known to provide a variable orifice prechamber in reciprocating engines to achieve certain advantages. Included in the advantages is that wherein, during initial stages of combustion, high turbulence and low ignition lag are achieved. Another advantage is that, while in the later stages of combustion, the engine acts much like a direct injection engine having good fuel economy and low heat rejection characteristics.
Generally, these advantages are achieved by regulating the rate of exit of combustion gases from the prechamber so as to cause the combustion process to take place at substantially constant pressure and at a rate approaching that of the theoretical ideal, all as discussed in the previously identified Eyzat et al patent.
Eyzat et al achieve the foregoing characteristics in a structure wherein an opening interconnecting a cylinder and a prechamber is opened at a desired rate by a protrusion carried on a reciprocal piston. Quite obviously, this approach cannot be employed in rotary engines wherein rotary pistons do not move reciprocally, but rather, undergo both rotational and translational movement.